Application of A-C Corrosion Monitor to Localized Corrosion
Application of A-C Corrosion Monitor to Localized Corrosion
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交流腐蚀监测在局部腐蚀中的应用
DOI：
10.3323/jcorr1974.28.12_638
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发表时间：
1979
期刊：
影响因子：
--
通讯作者：
S. Haruyama
中科院分区：
文献类型：
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作者：
T. Tsuru;R. Maeda;S. Haruyama
利用本实验室最新研制的交流自动腐蚀监测仪，对304不锈钢的局部腐蚀进行了研究，特别是对局部腐蚀的发生进行了研究。交流腐蚀监测仪允许记录试件净腐蚀速率的时间进程。不锈钢在NaCI溶液中的腐蚀速率在初始阶段相对较低，但在一定的孵化时间后，腐蚀速率迅速增加了40多倍，表现为点蚀。同时还发现，在孕育时间内，腐蚀速率越高，孕育时间越短。有人工缝隙的试件的缝隙腐蚀也有相似的孕育时间。316型不锈钢的缝隙腐蚀速率小于304和304-L不锈钢，且缝隙腐蚀速率还与阳极/阴极面积比有关。由于交流腐蚀监测仪测量的净腐蚀速率与根据试件失重估算的腐蚀速率非常一致，因此发现该腐蚀监测仪不仅可以监测一般腐蚀，而且还可以监测局部腐蚀。
The localized corrosion of type 304 stainless steel was investigated using the a-c automatic corrosion monitor deviced recently in our laboratory, with special interest to detect the initiation of localized corrosion. The a-c corrosion monitor permits to record the time-course of the net corrosion rate of specimen. The corrosion rate of the stainless steel in NaCI solution was relatively low at initial periodes but, after certain incubation time, it increased rapidly by more than forty times indicating a pit propergation. It was also noticed that higher the corrosion rate during the incubation time, shorter the incubation time. A similar incubation time was also observed on crevice corrosion of the specimen with an artificial crevice. The rate of crevice corrosion of type 316 stainless steel was less than that of type 304 and 304-L, while the rates also depended on the ratio of anode/cathode area. Since the net corrosion rates measured by the a-c corrosion monitor were well consistent with those estimated from the weight loss of the specimen, it is found that the corrosion monitor can be used to monitor not only general corrosion but also localized corrosion.